Tone-modifier



E. F. COPP. T6NE MODIFIER.

APPLICATION FILED APR.29| I920.

- Patented Sept. 28,1920.

' In ven tor:

UNITED STATES Par-ear err-ice.

EAR-L F. COPP, 0F MONTCLAIR, NEW JERSEY.

TONE-MODIFIER.

Specification of Letters Patent.

Patented Sept. 28, 1920.

Application filed April 29, 1920. Serial No. 377,429.

To all whom it may concern.

Be it known that I, EARL F. Corr, a citizen of the United States, and a resident of Montclair," Essex county, and ,Stateof New,

supporting means therefor-and by which the same may be adjusted toward and. away from the diaphragm of the sound box.

The invention involves various other novel features of construction, combinations and arrangements of parts, as will be disclosed in the-following specification.

In the accompanying drawing I have illustrated the invention embodied in several of the diflerent possible forms thereof, but

wish it understood that the same may be further modified and changed witho-ut'departure from the true spirit and scope of the inventionas herein defined and claimed.

In the drawing referred to: Figure 1 is a perspective View, and Fig. 2 is a sectional view of one of the simplest forms of the invention. 7 f Fig. 3 is another sectional View, illustrating a modification in the form of the adjusting device.

Figs. 4 and 5 are face and sectional views respectively of another form ty ng element.

Figs. 6 and 7 are face and sectional views of tone modirespectively, illustrative of another form of tone modifying means and the adjustment thereof.

i In the present illustrations. I have shown. in each instance the invention as made in the form of an attachment engageable over an ordinary sound box and have illustrated the sound box as of the usual conventional type, involving a box body 10, containing a diaphragm 11 to which there is connected the usual stylus lev v According to an invention, the tone is controlled by a damping action on the diaphragm and by reducing the area which is free to vibrate.

In the form of the invention first disclosed (Figs. 1 and :2), the controlling element consists of a pad 15 of resilient or semi-resilient material, such as felt, rubber or the like, carried by a plate or plates 16 and which is adjusted with respect to the diaphragm means of a screw 17.

This adjusting screw is shown as mounted in a support 18 in the form of a spider having spring supporting arms 19 clipped over the rim of the sound box and is shown as connected with the backing plates 16- of the pad by means of a bracket 20 arched" over the stylus lever. This screw is further- ,more shown as shouldered atits inner end at 21 and as connected by means of this shouldered portion with the head of the arched bracket and therefore capable of shifting the tone modifying pad in both directions.

To prevent rotation of the pad, I have shown a pin 22 projecting inwardly from the, screw support 18 through the head of the arched bracket, said bracket sliding thereover as the screw is turned in one direction or the other. I

In order that the pad shall not interfere with the free action of the stylus lever, I have shown the sameas having a slot 23 extending inward from the edge thereof, past the point where the stylus lever is -attached to the diaphragm, this making the pad generally of horse shoe shape.

The device in the form illustrated is applied to a sound box by simply sna11 ping the spring arms over the rim of the sound box. If the sound produced is too loud or strident,

vor otherwise oliijectionablc, the adjusting screw is turned to carry the pad inward into engagement with the face of the diaphragm, the screw being adjusted until the pressure of the pad upon the diaphragm is sufiicient to modify or softenthe tone to the desired extent, the pad yielding to enable this gradual modification. v

The location of the adjusting screw permits of this sound modifying adjustment while a record is being played, so that the efiects may be directly followed and adjustments made until the desired results are obtained. When the pad is adjusted outwardiyand entirely free of the diaphragm,

I modify the tone.

' butso lon In the form of the invention illustrated in Fig. 3, the tone modifying pad is employed as before, but in this instance, the adjustment of the same is accomplished'by means of a cam 24 pivoted on the supporting bridge piece or spider at 25 and arranged to bear; .on the outer end of the pad supporting A spring ,27 is-shown provided for the supporting pin outwardly and shift n'g the outer end of the pin is shown as seating may set the cam for in notches or pockets 28 provided in the rim of the cam so as to give certain set ad- The cam is shown as provided lever 29 and suitable indica tions may be provided so that an operator justments.

dium, etc.

In the form ,of the invention dis'closedin Figs. 4 and 5, the modifying effect is obtained by means'of a spring 30 of spiral conformation, supported at its center by a screw 31 which is adjustable similarly to the, screw 17 for the. purpose of shifting the spring toward and away from the diaphragm.

As this screw is turned to carry the spring element toward the diaphragm, "the outer or larger convolution of the spring will be engaged with the diaphragm and then as the screw is turned farther, succeeding inner convolutions of the spring will be brought into contact with the. face of the diaphragm. This results in .the free vibrating area of the diaphragm being gradually reduced and on substantially concentric lines. Also, as the active area of the diaphragm is reduced in size, the pressure on the diaphragm is increased andthis has a further modifying effect on the sound-pro duced.. p

Preferably, the convolutions of the spiral .spring which touch the diaphragm are provided with a rubber or other resilient covering, as indicated at 82.

This same progressive reduction in the active area of the diaphragm with gradual increase of exerted pressure may be accom- -plished in the first form ofthe invention illustrated. By making the resilient pad of conical or tapered construction, as indicated at 33, it will be engaged with the dia-.

phragm first at its outer edge andwill then, as it is compressed, gradually engage other inwardly located portions and thus gradually reduce the free area of the diaphragm.

Tone modifying effects similar to those described are attained in the form of the in-' vention illustrated in Figs. 6 and '7 by the provision of a plurality of pads 34f mounted 4 l d, oft, (4 m on spring arms which latter are canted or lncllned inwardly mounted on the sound box and carrying 35 pivoted on the pins 36,

toward the center of the diaphragm so that in the illustration, by means of an adjusting ring 37, rotatably p pins 38 working in cam, slots 39 in the spring arms.

It will be clear that upon the rotation of the adjusting ring 37, the pad carrying arms 35 will be swung inwardly or out wardly, as the case may be, and will in their inward swinging movement increase the tension of the pads on the diaphragm at the same time that the free area of the .diaphragm' is being gradually reduced. In the outer position of the arms, the pads will preferably stand free of the diaphragm, so

that, as in the constructions previously described, the diaphragm may, whendesired,

be left" free to vibrate in'the usual ,way. a

I find, with this' invention, that-not only is it possible to' control the volume of sound,

but also that the discordant sounds frequently produced can be eliminated and that the tone or musical quality can be greatly improved.

To avoid any possibility of breaking or injuring the diaphragm, prefer to limit the extent to which the tone modifying element may be tensioned against the same.

.Thus, in Figs. 2 and 5,1 have indicated how there may be provided a stop 40 on the adjusting screw which, as the screw is turned inwardly, will come into engagement with the hearing which supports the screw and will, therefore, positively limit the amount of tension which can be applied to the diaphragm. This stop also, it will.-be clear, limits the final reduction in size of the free area of the diaphragmlVhat I claim is:

1. A tone modifier for phonographs comprisingtone modifying means operable to engage successively smaller areas of the diaphragm of a sound box, and a control device for thus operating said tone modifying means to successively reduce the free vibrating area of the diaphragm.

2. A tone modifier for phonographs comprising a resilient tone modifying element and means for causing the same to succes-" sively reduce the free vibrating'area of the ing the pressure of said element on the diaphragm as the free area of the diaphragm is restricted.

4. A tone modifier for phonographs comprising a resilient conical spring supported with the base of the same toward the diaphragm of a sound box, and means for ringing successively smaller convolutions of the same against the diaphragm independently of the stylus.

5. A tone modifier for phonographs comprising a resilient conical element and means for variably tensiomng the same against the diaphragm of a sound box. independently of and means for forcing the same with increased pressure toward the sound box to thereby bring successive portions of the same into engagement. faith the diaphragm and to gradually increase the pressure of the same against the diaphragm.

7. The combination with the of a phonograph, of means for pressure thereto.

8. A tone modifier for phonographs comprising a tone modifying element, means for variably tensioning the same against the diaphragm of a sound box and adjustable means for positively limiting the extent of such adjustment.

9. A tone modifier for'phonographs comprising a tone modifyingpglement gradually cngagea ble with successively smaller areas of the diaphragm of a sound box, means for gradually adjusting said elem nt into engagement with s lch suecessively smaller areas to thereby SIICCGSSIVQ'ly f IT GdHCG the free and means In Witness whereof I April, 1920.

EARL F. COPR.

diaphragm 

